workshop “cognitive and motor functions of the vestibular...
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Workshop “Cognitive and Motor Functions of the Vestibular System”
5-6th July 2018, Aix-Marseille University
Thursday, July 5th 8h00 - 9h00 Welcome of the participants
9h00 - 9h15 Welcome and introduction to the workshop (J. Blouin, C. Lopez)
9h15 - 10h00 Plenary Lecture, Bigna Lenggenhager, University of Zurich, Switzerland (Chairwoman Elisa Ferrè) The plastic self: how vestibular signals influence the sense of self and embodied cognition
10h00 - 11h00 Oral session 1 (Chairwoman Elisa Ferrè)
10h00 Vestibular modulation of visuomotor feedback gains Leonie Oostwoud Wijdenes, Nijmegen, Netherlands
10h20 Unusual findings as the good evolution of a successfully treated recent positional vertigo that was accompanied by the resolution of a very old motion sickness
Thomas Richard-Vitton, Vitrolles, France
10h40 Different responses to vestibular stimulation and background motion in fast pointing Yajie Zhang, Amsterdam, Netherlands
11h00 Framiral / Sponsor, Alain Zeitoun
11h05 - 11h30 Coffee break
11h30 - 12h15 Plenary Lecture, Raymond Reynolds, University of Birmingham, U.K. Coordinate transformations for vestibular control of balance
12h15 - 13h00 Oral session 2
12h15 Effects of caloric vestibular stimulation on cognitive and motor symptoms of Parkinson’s disease David Wilkinson, Kent, U.K.
12h35 Postural control under Vestibular Extremely Low Frequency Magnetic Fields Stimulations Nicolas Bouisset, London (Ont), Canada
12h55 Virtualis / Sponsor, Franck Assaban
13h00 - 15h00 Lunch and Poster session
15h00 - 17h00 Oral session 3 (Chairperson: Jocelyne Ventre-Dominey)
15h00 Changes in intrinsic functional brain connectivity after first-time exposure to gravitational alterations by means of parabolic flight
Angelique Van Ombergen, Antwerp, Belgium
15h20 A vestibular-gravitational contribution to perceived body weight Elisa Ferrè, Royal Holloway, U.K.
15h40 Visual, proprioceptive and vestibular information for perception and action. Insights from proprioceptively-deafferented patients
Fabrice Sarlegna, Marseille, France
16h00 Shared brain areas underlying simulated and perceived self-motion Gianluca Macauda, Bern, Switzerland
16h20 Using virtual reality for sensorimotor learning and vestibular recalibration Jean-Pierre Bresciani, Fribourg, Switzerland
16h40 Time will tell which neural circuit to use for pointing home position after body displacement Jean Blouin, Marseille, France
17h00 - 17h45 Plenary Lecture, Patrick Haggard, University College of London, U.K (chairman Michel Guerraz) The vestibular body
17h45 End of Day 1
Friday, July 6th 8h30 - 9h00 Welcome of the participants
9h00 - 9h45 Plenary Lecture, Pieter Medendorp, Radboud University, The Netherlands Vestibular contributions to spatial updating and target selection (chairman Jean-Pierre Bresciani)
9h45 - 10h45 Oral session 4 (chairman Jean-Pierre Bresciani)
9h45 Galvanic vestibular stimulation and executive functions Corina Schöne, Bern, Switzerland
10h05 Role of the gravitational signals on the visuo-proprioceptive integration underlying the control of goal- oriented hand movements Michele Tabliabue, Paris, France
10h25 Direct and lumbar-relayed vestibular inputs onto thoracic postural motoneurons in Xenopus Didier Leray, Bordeaux, France
10h45 - 11h10 Coffee break
11h10 - 12h10 Oral session 5 (chairman Christian Chabbert)
11h10 How visual input stabilizes posture in patients with bilateral vestibular hypofunction Michel Lacour, Marseille, France
11h30 The impact of bilateral vestibulopathy on cognition in humans Mieke Dobbels, Antwerp, Belgium
11h50 A vestibular system to optimize motor planning Jérémie Gaveau, Dijon, France
12h10 - 12h55 Plenary Lecture, Paul Smith, University of Otago, New Zealand Vestibular contributions to hippocampal and striatal function (chairman Christian Chabbert)
12h55 - 14h45 Lunch and Poster session
14h45 - 16h05 Oral session 6 (chairwoman Laurence Mouchnino)
14h45 Cognitive repercussions of bilateral vestibular loss in humans Griet Mertens, Edegem , Belgium
15h05 Social modulation of vestibular information processing Estelle Nakul, Marseille , France
15h25 Beaming into a robot: How visuo-vestibular synchrony influences body-self and social cognition Jocelyne Ventre-Dominey, Lyon, France
15h45 How vestibular disorders distort own-body perception and the sense of self Christophe Lopez, Marseille, France
16h05 End of the Workshop
Posters
1. Can Vestibular Signals Influence the Temporal Orienting of Attention? Saghi Arabi, Kent U.K. 2. Changes in body spatial representation after unilateral vestibular loss are modulated by the side of the lesion and the
post-lesion delay. Liliane Borel , Marseille, France 3. Neuro-behavioural Impairment in Military Veterans with Mild Traumatic Brain Injury and Vestibular Disorder. Emma
Denby , Kent, U.K. 4. Videonystagmography evaluation of dynamic asymmetry of vestibulo-ocular reflex (VOR) responses, after unilateral
peripheral loss. Comparison of passive rotational testing versus active head movements testing. Olivier Dumas, Lyon, France
5. Sharp foot pressure enables cortical sensory facilitation during natural standing: Combined behavioral, EEG and microneurographic approaches. Marie Fabre, Marseille, France
6. Getting ready for Mars: how the brain perceives new gravitational environments. Maria Gallagher, London U.K. 7. Vestibular Facilitation During a Virtual Morris Water Maze Task. Annita Gkioka, Kent, U.K. 8. Vestibulospinal control of axial and limb muscles : static, dynamic, and microgravity conditions. Etienne Guillaud,
Bordeaux, France 9. Changes in Functional brain activation with aging during hand movement perception. Caroline Landelle, Marseille,
France 10.How gravity influences vection induced by galvanic vestibular stimulation. Alexandra Séverac Cauquil, Toulouse,
France 11.Vestibular contributions to short-term memory. Laura Smith, Kent, U.K.
With support from and
Bigna Lenggenhager
University of Zurich
The plastic self: how vestibular signals influence the sense of self and embodied cognition
An increasing body of both theoretical and empirical work suggest that the bodily self is highly
plastic and based on a probabilistic integration of bottom-up sensory processing and top-town
expectancies. Such notion of a plastic self opened up a new line of research trying to manipulate
and study the bodily self by exposing individuals to situations of multisensory conflicts. While
this research has traditionally exploited exteroceptve signals, increasing evidence suggests an
important contribution of interoceptive and vestibular signals. Presenting findings from patients
and heathy participants, I will explore the question on how vestibular cues might contribute to
our stable sense of a bodily self and how alterations in vestibular processing might alter our
sense of a bodily self and related cognition.
Vestbular modulation of visuomotor feedback gains
Leonie Oostwoud Wijdenes, Robert J. van Beers, W. Pieter Medendorp
Reaching movements can be flexibly adjusted during execution in response to changes in
the world, for example a target position perturbation. The velocity with which the hand
corrects for a perturbation, i.e. the gain, demonstrates a task dependency and modulates
throughout the movement. Sophisticated gain modulation is a result from the integration of
visual, tactile and proprioceptive information about the position of the body into a state
estimate. Here we asked if the vestibular system also contributes to this state estimate for
the online control of reaching. In two experiments participants were seated on a vestibular
sled that translated them forward or backward with a low or high acceleration profile.
Compared to the high acceleration profile, the low acceleration profile was a slower
translation (Exp1) or a shorter translation (Exp2). Participants were instructed to move
their right index finger in the sagittal plane toward a body-fixed target, which jumped
perpendicular to the main movement direction in half of the trials. The jump could occur
100, 200 or 350 ms after trial start. In both experiments we found a main effect of sled
acceleration: the visuomotor feedback gain was higher for higher accelerations. However,
contrary to the stationary situation, feedback gains were not affected by jump timing. An
Optimal Feedback Control model that has knowledge about the accelerations under which
the movement is executed cannot explain the lack of a jump timing effect. Analyzing the
gains for the first and second half of the experiment separately showed that the visuomotor
feedback gains decrease over the course of the experiment. This suggests that vestibular
information does contribute to the state estimate for the online control of reaching.
Unusual findings as the good evolution of a successfully treated recent positional vertigo that
was accompanied by the resolution of a very old motion sickness
Thomas Richard-Vitton, Vitrolles, France
Since the initial description of the hypothesis of the canalithiasis to explain the BPPV about
thirty years ago, no one has clearly propose some updates. The goal of this short presentation is
to show that the disorders secondary to the migration of otoconies into one or more
semicircular canals could lead to other symptoms that classic described BPPV.We made a study
two years ago, not yet published, with a laboratory specialized in fluid mechanic studies. We
wanted to show with the help of a mathematical model that the particles (otoconies), that are
well known to be ranged from 3.5 to 30 micrometers size, have not the same velocity of
migration with gravity action. The results shown that some of these particles may need more
than one hour to make the travel from the cupula to the exit of the canal with only the
gravitational force. That lead to the hypothesis that some of the canaliths disorders may have
others expression that classic BPPV, particularly unsteadiness, motion sickness, nausea without
disequilibrium. We present the case of an old man, 85 years old, that resolved a very strong
thirty years old motion sickness after a therapeutic session to treat a two months history
positional vertigo.
Different responses to vestibular stimulation and background motion in fast pointing
Yajie Zhang, Eli Brenner, Jeroen B.J. Smeets
Department of Human Movement Sciences, Vrije Universiteit Amsterdam, the
Netherlands If one makes a fast goal-directed arm movement, self-motion should be compensated. So, stimuli that perturb balance due to perceived self-motion may cause compensatory responses in arm movements. Moving a background surrounding a stationary target indeed induces postural responses and deviations in goal-directed arm movements. If these deviations are due to perceived self-motion, vestibular stimulation should also lead to deviations in hand movements. Therefore, we compare responses in posture and arm movement to perturbations of the vestibular and visual information about self-motion. In a standing position, participants tried to tap on targets shown on a horizontal screen as fast as possible. Vestibular perturbations (galvanic vestibular stimulation) and visual perturbations (background motion) were applied in separate blocks. Within each block, 2/3 of the trials involved postural perturbation, the other trials involved target displacements. The perturbations took place during the hand movement. Kinematic data of hand and head were collected. Participants made movements with durations of 280 ± 50 ms. In response to the vestibular perturbation, the lateral head responded vigorously but the hand hardly responded. In contrast, both the head and hand responded considerably to background motion. The head response started about 70 ms after the start of vestibular perturbation, about 50-60 ms earlier than the head and finger responses to background motion. These results suggest that the hand following response to background motion is not the result of compensation for perceived self-motion. Key words: Galvanic vestibular stimulation, background motion, reaching, postural control
Coordinate transformations for vestibular control of balance
Raymond Reynolds
University of Birmingham, U.K.
The vestibular system is sensitive to head motion but to maintain balance the information it provides
must first be transformed from head to body coordinates. Accurate proprioception is crucial for this
process. I will present a series of experiments which investigate the transformation process using
Galvanic Vestibular Stimulation (GVS). GVS activates the vestibular system in a very specific manner,
evoking a precise sensation of head roll motion. This, in turn, evokes a whole-body balance response.
The sway response must be oriented accurately to compensate for the (sensed) perturbation. I
demonstrate situations in which the accuracy of the sway response is adversely affected. These include
illusions of body orientation and prolonged inactivity due to bedrest. In conclusion, vestibular control of
balance cannot be considered in isolation, but always in conjunction with proprioceptive sensation.
Effects of Caloric Vestibular Stimulation on Cognitive and Motor Symptoms of
Parkinson’s Disease
David Wilkinson1, Aleksandra Podlewska1, Mayur Bodani2, Mohamed Sakel3, Sarah
Banducci4 & Kristen Ade4
1School of Psychology, University of Kent, Canterbury, UK
2Neuropsychiatry Service, Kent & Medway NHS and Social Care Partnership Trust, UK
3East Kent Neuro-Rehabilitation Service, East Kent Hospitals University NHS Foundation
Trust, Canterbury, UK
4Scion Neurostim, LLC, North Carolina, USA
Pre-clinical study gives reason to believe that vestibular stimulation may provide adjuvant
therapy for Parkinson’s disease (PD). Here we assessed, for the first time, the effect of
repeated sessions of caloric vestibular stimulation (CVS) on both motor and non-motor
symptoms of PD in a randomised, controlled, double-blinded trial. 33 participants
diagnosed with PD and in stable receipt of dopamine replacement therapy self-
administered CVS in their homes twice daily for 8 weeks using a portable, solid state
stimulator. Participants were followed over a 4-week baseline, 8-week treatment and then
5 and 24 weeks post-treatment period during which time symptoms were monitored via
standardised clinical measures. Change scores between baseline and the end of treatment
showed that active, but not placebo, participants demonstrated clinically relevant
reductions in non-motor (most notably in attention/memory, depression, anxiety and
sleep/fatigue) and motor (including bradykinesia, rigidity and tremor) symptoms. These
gains were most evident 5 weeks after active treatment had ceased, but had started to
recede when re-assessed at 24 weeks post-treatment. We conclude that repeated CVS
may provide a safe and durable adjuvant therapy for motor and non-motor symptoms
associated with PD. From a theoretical perspective, the observed durability and
widespread nature of gain may suggest that the vestibular system can support a degree
of neuroplastic change across cognitive and motor systems.
Postural control under Vestibular Extremely Low Frequency Magnetic Fields Stimulations
Nicolas Bouisset1, 2, Sébastien Villard1, 3, Daniel Goulet7, Michel Plante7, Martine Souques6, François Deschamps5, Geneviève Ostiguy7, Jacques Lambrozo6, Alexandre Legros1,
2, 3, 4, 8
1Human Threshold Research Group, Lawson Health Research Institute, London, ON, Canada 2Department of Kinesiology, Western University, London, ON, Canada
3Department of Medical Biophysics, Western University, London, ON, Canada 4Department of Medical Imaging, Western University, London, ON, Canada
5RTE, Département Concertation et Environnement, Cœur Défense, Paris, France 6Service des Études médicales, EDF, Levallois-Perret Cedex, France
7Hydro-Québec, Montréal, Québec, Canada 8EuroMov, Université de Montpellier, Montpellier, France
Introduction - Extremely low frequency magnetic fields (ELF-MF) induces electric fields and currents within the human body potentially modulating vestibular function. Furthermore, postural instabilities can be induced by direct (DC) or alternative (AC) galvanic vestibular stimulation (GVS)1. Cathodal currents are thought to depolarize vestibular’s afferents leading to an increase in its firing rate, whereas anodal currents have opposing effects. Asymmetry in firing rates produce postural control modulation1. The goal of this study is to measure the acute impact of ELF-MF exposures (up to 100 mT) on vestibular functions looking at postural modulations. DC-GVS was used as positive control. We hypothesize that ELF-MF induced currents should modulate the vestibular system and impact postural instability Methods - Thirty participants were tested during fourteen 20-second conditions spaced with 30 seconds of rest. The task consists in standing on a force plate, upon a 6-cm thick foam surface with the eyes closed. Sway characteristics were calculated off-line from the recorded center-of-pressure (COP) data. Five-second magnetic (100mT) and electric (2mA) stimulations were randomly delivered to the right vestibular system at 20 Hz, 60 Hz, 90 Hz, 120 Hz and 160 Hz. A cathodal DC-GVS stimulation was used as a positive control. Results - From the COP analysis only the ‘path length‘ in the frontal plane (representing the total length of the center-of-pressure (COP) excursion) is reported herein. A paired t-test show a significantly bigger sway path with DCGVS as compared to no stimulation (t11 = 6.1392, p < 0,001). The two-way ANOVA for repeated measure 2 (stimulation modalities) x 6 (frequencies) has not shown any main effect (modality F1,31 = 0.00015, p = 0.99; frequency : F5,310 = 1.80, p = 0.11) nor any interaction (F5,310 = 1.21, p = 0.30)). Discussion – Although vestibular motor outcomes are fast (e.g. 7ms for the vestibulo-ocular reflex), vestibular perception is slow (e.g. 500 ms after DC-GVS onset) 2. Loss of balance with DC-GVS is in reaction to perception of falling towards the cathodal side. At 20 Hz, the current’s period is 50 ms, which is under the time perception threshold. This might explain why our stimulations appear ineffective in modulating postural control even if the vestibular system is sensitive to frequencies up to 800 Hz 3. The results could also be explained by biomechanical filtering mechanisms4. Future vestibular ELF-MF studies should focus on vestibulo-ocular or vestibulo-cortical activity to avoid perceptual and biomechanical filtering and better characterize vestibular responses to ELF-MF. References 1. Fitzpatrick, R. C. & Day, B. L. Probing the human vestibular system with galvanic stimulation. J. Appl.
Physiol. 96, 2301–16 (2004). 2. Barnett-cowan, M. Vestibular Perception is Slow : A Review. Multisens. Res. 26, 387–403 (2013). 3. Curthoys, I. S. The new vestibular stimuli: sound and vibration—anatomical, physiological and clinical
evidence. Exp. Brain Res. 235, 957–972 (2017). 4. Forbes, P. A., Siegmund, G. P., Schouten, A. C. & Blouin, J.-S. Task, muscle and frequency dependent
vestibular control of posture. Front. Integr. Neurosci. 8, 94 (2014).
TITLE: CHANGES IN INTRINSIC FUNCTIONAL BRAIN CONNECTIVITY AFTER
FIRST-TIME EXPOSURE TO GRAVITATIONAL ALTERATIONS BY MEANS OF
PARABOLIC FLIGHT
AUTHORS: Angelique Van Ombergen, Floris L. Wuyts, Ben Jeurissen, Jan Sijbers,
Floris Vanhevel, Steven Jillings, Paul M. Parizel, Stefan Sunaert, Paul H. Van de
Heyning, Vincent Dousset, Steven Laureys, Athena Demertzi
ABSTRACT: Spaceflight severely impacts the human body. However, little is known
about how gravity and gravitational alterations affect the human brain. Here, we aimed
at measuring the effects of acute exposure to gravity transitions. We exposed 28 na ıve
participants to repetitive alterations between normal, hyper- and microgravity induced
by a parabolic flight (PF) and measured functional MRI connectivity changes. Scans
were acquired before and after the PF. To mitigate motion sickness, PF participants
received scopolamine prior to PF. To account for the scopolamine effects, 12 non-PF
controls were scanned prior to and after scopolamine injection. Changes in functional
connectivity were explored with the Intrinsic Connectivity Contrast (ICC). Seed-based
analysis on the regions exhibiting localized changes was subsequently performed to
understand the networks associated with the identified nodes. We found that the PF
group was characterized by lower ICC scores in the right temporo-parietal junction
(rTPJ), an area involved in multisensory integration and spatial tasks. The
encompassed network revealed PF-related decreases in within- and inter-hemispheric
anticorrelations between the rTPJ and the supramarginal gyri, indicating both altered
vestibular and self-related functions. Our findings shed light on how the brain copes
with gravity transitions, on gravity internalization and are relevant for the understanding
of bodily self-consciousness. (Van Ombergen et al, Scientific Reports, 2017).
A vestibular-gravitational contribution to perceived body weight
E. R. Ferrè1, T. Frett2, P. Haggard3 and M. R. Longo4 1 Department of Psychology, Royal Holloway University of London, UK 2 Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Germany 3 Institute of Cognitive Neuroscience, University College London, UK 4 Department of Psychological Sciences, Birkbeck, University of London, UK
The weightlessness experienced by astronauts has fascinated scientists and the public.
On Earth, body weight is given by Newton's laws as mass times gravitational acceleration. That
is, an object’s weight is determined by the pull of gravity on it. We hypothesised that perceived
body weight is – like actual weight – dependent on gravity. If so, changes in the experienced
force of gravity should alter the experience of one’s own body weight. We asked participants to
estimate the weight of two body parts, their hand or their head, both in normal terrestrial gravity
and during exposure to experimentally altered gravitational fields, 0g and +1.8g during parabolic
flight and +1g using a short arm human centrifuge. For both body parts, there was a clear increase
in perceived weight during experience of hypergravity, and a decrease during experience of
microgravity. Our results show that experimental alterations of gravity produce rapid changes in
the perceived weight of specific individual body parts. Traditionally, research has focused on the
social factors for weight perception, as in the putative role of mass media in eating disorders. Our
results, in contrast, emphasize that the perception of body weight is highly malleable, and shaped
by immediate sensory signals.
Visual, proprioceptive and vestibular information for perception and action.
Insights from proprioceptively-deafferented patients.
Fabrice SARLEGNA, Institute of Movement Sciences, CNRS & Aix-Marseille University
Understanding the specific contributions of visual, proprioceptive and vestibular information
for perception or motor control often remains a challenge. Creative paradigms have been
developed and recently we had the opportunity to address these issues, and run some classic
protocols, with patients deprived of proprioceptive information. We hypothesized that a
massive loss of proprioception would lead to massive changes in perceptual and motor control
mechanisms. The idea that proprioceptively-deafferented patients substantially rely on visual
information as well as cognitive resources is well documented (Blouin et al. 1993; Teasdale et
al. 1993 ; Ghez et al. 1995) but we tested the hypothesis that deafferented patients could also
substantially rely on vestibular information for the perception of spatial orientation as well as
for spatially-oriented movements.
To assess the multisensory integration mechanisms underlying the perception of
object orientation, we (Bringoux et al. 2016) compared perceptual responses of a
deafferented patient (GL) with respect to age-matched controls in a Rod-and-Frame Test. In
this task, subjects had to align a visual rod with the gravitational vertical (i.e., Subjective Visual
Vertical: SVV) when facing a tilted or non-tilted visual frame. Such manipulation of the visual
cues revealed that the deafferented patient was fully dependent, and thus much more than
Controls, on spatial cues issued from the visual frame when judging the SVV.
To assess the mechanisms underlying the perception of self-orientation, subjects
participated to another task in which they had to report whether they felt tilted when facing
very slow pitch tilts of the body and/or visual surroundings away from vertical. In contrast to
to the findings on controls, and in the Rod-and-Frame Test, the deafferented patient did not
report any feeling of tilt when the visual scene was substantially tilted (up t o18°). Moreover,
the patient never reported any sensation of tilt up to 18◦, contrary to controls, hence showing
that she did not rely on otoliths signals for the detection of very slow body tilts.
To assess the mechanisms underlying the perception of self-generated movements,
we (Miall et al. 2018) then assessed the ability of deafferented patients and controls to detect
the direction of force pulses applied on the moving arm. With vision, patients performed as
well as controls but without vision, impairments were observed. However, performance was
better than expected and suggests that without visual and proprioceptive feedback about limb
position and movement, one could determine the force direction from head motion, detected
either through cervical afferents or vestibular signals .
Overall these studies show that a massive proprioceptive deficit substantially alters the
perception of spatial orientation, and that the use of the remaining sensory inputs differs
depending on the nature of the judgment (about an object orientation or about the self). Our
findings thus highlight the specificity of the multisensory integration, and compensatory,
mechanisms underlying perception and action.
Shared brain areas underlying simulated and perceived self-motion
Gianluca Macauda1, Marius Moisa2, Christian Ruff2, Fred W. Mast1, Lars Michels3*, Bigna Lenggenhager4*
* Shared last-authorship
1 Department of Psychology, University of Bern, Bern, Switzerland, 2 Laboratory for Social and Neural Systems Research, Department of
Economics, University of Zurich, Zurich, Switzerland. 3 Clinic for Neuroradiology, University Hospital Zurich, Zurich, Switzerland 4 Cognitive
Neuropsychology, Department of Psychology, University of Zurich, Zurich, Switzerland
Mental imagery is an essential ability to infer the future state of one's body. Neuroimaging studies
have shown that mental simulations activate sensory or motor structures in the brain that are
associated with an overt action or a perception generated by external stimuli.
It is suggested that the mental projection of one’s own body to a different spatial location (egocentric
mental rotation) is based on brain areas that are also involved in processing actual self-motion.
Evidence for the involvement of vestibular information in simulated changes of self-location stems
mainly from behavioural experiments, where healthy participants showed an altered capacity for
egocentric mental rotation during vestibular stimulation, and vestibular patients showing a reduced
ability to perform egocentric mental rotations. However, those findings are challenged by the
conflicting nature of the vestibular stimulation used in different studies, and the cognitive tasks that
imply different individual strategies. In the current study we addressed those issues and used fMRI to
investigate the brain areas that underlie both, simulated changes of the self in mental space and
vestibular processing within the same individuals. Participants performed an egocentric mental
rotation task during simultaneous Galvanic Vestibular Stimulation (GVS) or sham stimulation. In line
with previous literature, we hypothesized that GVS negatively affects participants’ egocentric mental
rotation ability. More importantly, at the neural level we expected an overlap between brain areas
activated during vestibular processing and egocentric mental rotation independently within the
parieto-insular vestibular cortex (PIVC), which is a core area in vestibular processing.
As predicted, the fMRI data showed an overlap of brain activity within the PIVC for both egocentric
mental rotation and vestibular processing. In contrast to our expectations, GVS did not influence the
ability to perform egocentric mental rotation.
Our results provide the first neural evidence for shared neural mechanisms underlying perceived and
simulated self-motion. They also suggest that the vestibular stimulation was not effective enough to
impair egocentric mental rotation. We conclude that mental rotations of one’s body rely on the PIVC,
but also suggest that those mental simulations of one’s body might be protected from external
interference.
Using Virtual Reality for sensorimotor learning and vestibular recalibration
JP Bresciani, J Schomaker, J Tesch, H Bischoff, HH Bülthoff
Stroke patients very often suffer from hemi-lateral motor deficits. Neurorehabilitation training
paradigms aim at aiding these patients re-learning skills impaired by the stroke episode. Because of the
flexibility, realism and high level of experimental control it provides, Virtual Reality (VR) potentially
constitutes an extraordinary tool to facilitate neurorehabilitation. Specifically, virtual environments can
be used to present adaptive and motivating scenarii that can be tailored to the specific needs of the
patient. In line with this, and in order to optimize the potential benefits of VR, it is important to determine
which conditions best facilitate sensorimotor learning. We used a state-of-the-art VR set-up with body-
motion recording and an avatar animated in real-time to test how sensorimotor learning is affected by
factors as the realism of the visual scene and the viewpoint.
Participants seating on a motorized wheelchair had to maintain their stretched arm fixed in space despite
whole-body rotations. After a test session in which body rotations occurred without visual information,
participants were exposed to a visuo-vestibular adaptation, and then tested again in a test session
identical to the first one. In the adaptation phase, biased visual information about motion amplitude was
provided during body rotations via a head-mounted display, so that participants learned a biased visuo-
vestibular mapping. Visual information relative to the body and to the environment was systematically
manipulated. We show that the realism of the visual scene and the viewpoint are factors affecting the
amplitude of sensorimotor adaptation.
Time will tell which neural circuit to use for pointing home position after body displacement
Jean Blouin1, Anahid H. Saradjian1, Jean-Philippe Pialasse2, Gerome Manson1,3,
Laurence Mouchnino1, Martin Simoneau2 1CNRS/Aix-Marseille University, Marseille; 2Laval University , Québec; 3University of Toronto, Toronto
After exposure to passive rotation, one is able to point to the initial body position even without visual
feedback. This suggests that goal-directed arm movements can be planned on the basis of vestibular
information. We performed EEG recordings to investigate the neural processes underlying the planning
of these vestibular-guided arm movements. In Exp 1, 9 subjects pointed with their right arm in response
to a 50 ms tone that occurred after either a 20°, 30°, or 40° CCW rotation. Mean EEG activity of several
ROIs of the frontal and posterior cortex were computed during the movement planning (MP= time
between the tone and arm EMG onset). To examine the time course of activation patterns, EEG activity
during MP was separated into quintiles. Activity in each bin was compared to a condition in which no
pointing was performed after the tone.
Aside from the sensorimotor cortex, the PFC and dCC cortices were the only ROIs showing significant
task-related activities. The activity of the left PFC was greater in the reach condition throughout MP. This
sustained activity provides electrophysiological support to the suggestion, issued from lesion studies,
that the PFC is involved in task-relevant memorization of vestibular signals (Berthoz 1987). The activities
of both dCC were greater only in the last 20% of MP. This is consistent with the idea that the dCC
constitutes a source of descending commands for the arm movements (He & Strick 1995) and
contributes to stock egocentrically encoded spatial information in working memory (Ma et al 2012).
In Exp 2 (9 subjects), the imperative 50 ms tone signal to move the arm occurred 8 s after rotations. EEG
activity was compared to a condition with the tone, but with neither rotation nor reaching. Similar reach
activities in PFC and dCC as in Exp 1 were noted. But we also found reach related activity in the aCC that
increased over a sustained activity, suggesting that the aCC is involved in the control arm movements
that rely on working memory (Pauss 2001). Furthermore, progressive increases of activity were observed
in the dPMC and in the vPMC. These observations are consistent with studies showing that the dPMC is
involved in the selection of motor responses on the basis of spatial cues (Wise 1982) and studies
showing that the vPMC is involved in space perception and in transforming spatial locations into arm
motor actions (Rizzolatti 2002).
A progressive increase of activity was also found in both sPPC, areas known to use multimodal space
representation to plan movement (Andersen 1997). In the left iPPC, the activity was greater in the reach
condition throughout MP but also tended to increase (p = .07), as it significantly did in the right iPPC.
These areas are known to contain multimodal representations of space relative to the hand (Rozzi et al
2008). Overall, our findings are compatible with the existence of 2 neural networks capable of planning
arm movements on the basis of vestibular cues. A frontal, fast-operating sensorimotor network which
relies little on visuospatial representations, and a more complex parieto-frontal network, which might
rely on higher visuospatial processes and which would contribute to the planning process when a gap is
introduced between body motion and the goal-directed arm movement.
Patrick Haggard
University College of London, U.K.
Title: The vestibular body
Vestibular contributions to spatial updating and target selection
Pieter Medendorp, Radboud University, The Netherlands
The vestibular system, which detects motion and orientation of the head in space, is known to
be important in controlling gaze to stabilize vision, ensuring postural stability and in providing
our sense of self-motion. While the brain’s computations underlying these functions are
extensively studied, the role of the vestibular system in higher level sensorimotor functions is
less clear. In my talk, I will outline the modeling, behavioral and physiological approaches we
took to understand how healthy participants and patients make perceptual judgments, select
targets and responses, and perform motor actions when their body translates or adopts
different orientations relative to gravity. I will also identify future directions for theoretical,
behavioral, and neurophysiological investigations that follow from these results.
Galvanic vestibular stimulation and executive functions
Corina G. Schöne1, 2, 3, & Fred W. Mast1, 2
1 Department of Psychology, University of Bern, Switzerland
2 Center for Cognition, Learning and Memory, University of Bern, Switzerland
3 Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, Bern
University Hospital, University of Bern
Patients with peripheral vestibular disease have problems in executive functions but there is
not much knowledge about the direct vestibular influence on executive functioning. We used
the method of galvanic vestibular stimulation (GVS) to induce a mild vestibular impairment
in healthy participants and investigated its effect on core domains of executive functions
(inhibition, working memory, cognitive flexibility). Seventy-nine healthy participants solved
two executive tasks (n-back task, Stroop task) twice, first as a baseline measure and then
again during the application of bilateral bipolar sinusoidal GVS. Participants were randomly
assigned to three different stimulation protocols: 1.) Suprathreshold GVS (2mA) to induce the
vestibular impairment, 2.) subthreshold GVS (0.8mA) or 3.) sham GVS (0mA). Participants
receiving suprathreshold GVS showed an impaired performance in the working memory task
whereas participants in the subthreshold GVS or the sham GVS group did not show an
impaired working memory performance. Inhibition and cognitive flexibility performance did
not differ between groups. Our results show that artificially induced vestibular impairment
leads to a selective negative effect on working memory performance. This knowledge can
help to understand executive deficits in patients with peripheral vestibular disease and should
guide new treatment options.
Role of the gravitational signals on the visuo-proprioceptive integration underlying the control of goal-oriented hand
movements.
Michele Tagliabue1, Mathieu Beraneck1, Joseph McIntyre1,2
1 Center for Neurophysics, Physiology, Pathology, UMR 8119, CNRS Universite Paris Descartes, Sorbonne Paris Cite,
Paris, France
2 Tecnalia Research and Development, Health Division, San Sebastian, Spain
The control of upper-limb movements aimed at reaching and grasping an object is highly multi-
sensorial. It is known, for instance, that the brain combines in an optimal fashion visual and
proprioceptive information to maximize the precision of target perception and movement control.
Nonetheless, the role of additional sensory inputs, such as the vestibular signals, has been less
investigated. In order to better understand whether and how the vestibular/gravitational inputs interact
with the control of hand movements, we are performing a series of experiments using virtual reality.
The experimental paradigm we use allows us to quantify motor performances and to estimate the
contribution of different sensory signals to movement control.
The results of these experiments have shown that the otolithic/gravitational signals play an important
role, not only as reference frame for visual and proprioceptive information encoding, but also in the
brain ability to make these two sensory modalities interact. To better understand this phenomenon,
we are studying how goal-oriented movements and the underlying sensory processing are affected by
different postures, such as head tilt with respect to gravity and/or supine position. Moreover, to
investigate whether these postural effects are mainly linked to the sensory system physiology or to
the brain propensity to treat sensory signals associated with the erect posture, we are also testing
whether and how the brain can adapt to long-term alterations of otolithic inputs. To this end, healthy
volunteers in a study involving a two month-long bedrest were asked to perform our virtual reality
protocol, before, during and after bedrest. Finally, to study more specifically the effects of short- and
long-term lack of gravitational/otolithic signals, a micro-gravity study based on a similar protocol is
ongoing on board of the International Space Station.
Direct and lumbar-relayed vestibular inputs onto thoracic postural motoneurons in Xenopus
Didier Le Ray & François M. Lambert
Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (UMR 5287, CNRS-Univ. Bordeaux)
Vestibular information is critical for controlling locomotion and posture. In many vertebrates, postural
control was demonstrated to rely mainly on vestibulospinal pathways acting directly on spinal axial
motoneurons. However, several studies in the last decade also suggested a substantial role of
propriospinal commands originating from locomotor generators during active locomotion. Especially,
in the adult Xenopus a lumbar drive onto thoracic motoneurons overwhelms descending inputs during
swimming. Given that some vestibulospinal fibers project onto the lumbar segments that shelter
locomotor generators, we investigated whether such a lumbo-thoracic pathway may relay vestibular
information and consequently, be involved also in the control of posture at rest. We show that thoracic
motoneurons exhibit particular dendritic spatial organization that allows them to gather information
from both sides of the cord. Both vestibular descending and lumbar ascending fibers converge to these
dendrites, and electrical stimulation demonstrated the functionality of such connections. We also
show that natural activation of inner ear endorgans triggers thoracic motoneurons discharges
reflecting both position and velocity components of the vestibular sensory-motor signal that is
mandatory to code for the appropriate postural adjustment. However, each component is mainly
conveyed by its dedicated pathway. These results complete the scheme of the vestibulospinal control
of posture by clearly demonstrating the existence of a novel pathway, which implicates a lumbar relay,
conveys specific vestibular inputs to thoracic motoneurons and underlies postural stabilization of the
trunk in the absence of active locomotion.
How eye movements stabilize posture in
patients with bilateral vestibular hypofunction
Michel Lacoura, Nadine Yavo Dossob, Sylvie Heuschenc, Alain Thiryd, Christian Van
Nechele, Michel Toupetf
ABSTRACT
Chronic patients with bilateral vestibular hypofunction (BVH) complain of oscillopsia
and great instability particularly when vision is excluded and on irregular surfaces. The real
nature of the visual input substituting to the missing vestibular afferents and improving posture
control remains however under debate. Is retinal slip involved? Do eye movements play a
substantial role? The present study tends to answer this question in BVH patients by
investigated their posture stability during quiet standing in four different visual conditions: total
darkness, fixation of a stable space-fixed target, and pursuit of a visual target under goggles
delivering visual input rate at flicker frequency inducing either slow eye movements (4.5 Hz)
or saccades (1.2 Hz). Twenty one chronic BVH patients attested by both the caloric and head
impulse test were examined by means of static posturography. The posturography data were
analyzed using non-linear computation of the center of foot pressure (CoP) by means of the
wavelet transform (Power Spectral Density in the visual frequency part, Postural Instability
Index) and the fractional Brownian-motion analysis (stabilogram-diffusion analysis, Hausdorff
fractal dimension). Results showed that posture stability was significantly deteriorated in
darkness in the BVH patients compared to normative data recorded in age-matched healthy
controls. Strong improvement of BVH patients’ posture stability was observed during fixation
of a visual target, pursuit with slow eye movements, and saccades. It is concluded that BVH
patients improve their posture stability by 1) using extraocular signals from eye movements
(efference copy, muscle re-afferences), and 2) shifting to a more automatic mode of posture
control when they are in dual-task conditions associating the postural task and a concomitant
visuo- motor task.
Key Words: Bilateral Vestibular Hypofunction Patients – static posturography – darkness –
visual fixation – slow eye movements - saccades
Title: The impact of bilateral vestibulopathy on cognition in humans
Authors: Bieke Dobbels 1,2, MD; Julie Moyaert 1, MSc; Griet Mertens 1,2, MSc, PhD; Paul Van de
Heyning 1,2, MD, PhD; Vincent Van Rompaey 1,2, MD, PhD.
Institution: Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital,
Belgium. Faculty of Medicine and Health Sciences, University of Antwerp, Belgium
Study objectives: Hearing loss have recently been recognized as an independent risk factor of
dementia. Likewise, growing evidence suggest a link between the vestibular system and cognition.
Our aim is to evaluate if patients with bilateral vestibulopathy (BV) suffer from spatial and non-
spatial cognitive deficits and to assess if these deficits are caused by their vestibular and/or hearing
loss.
Methods: 62 patients (59y±14) with an established diagnosis of BV according to the Barany criteria,
were included. All patients received audiometric and vestibular testing. Cognition was assessed by
the means of the Repeatable Battery for the Assessment of Neuropsychological Status, for hearing
impaired persons (RBANS-H). The RBANS measures 5 domains of cognition: immediate memory,
delayed memory, visuospatial abilities, attention and language. 72 healthy, normal hearing, controls
(69y±11) without vestibular complaints completed the RBANS-H.
Results: Overall, patients with BV had a worse total score then patients with BV without hearing loss
and healthy controls. In a first multiple linear regression model where there was no correction of
hearing loss, a statistically significant difference was found on total RBANS-score and on all subscales
except from delayed memory and visuospatial abilities. However, in a multiple linear regression
model with correction for hearing loss, these differences were no longer statistically significant
between the BV group and healthy controls. Moreover there was a statistically significant main effect
of hearing loss in the total RBANS scale and in all subdomains except from visuospatial abilities.
Conclusion: Our results confirm the previous findings of impaired cognition in BV patients, although
their was only a statistically significant main effect of hearing loss and not of vestibular loss.
A vestibular system to optimize motor planning
Gaveau J., Dickman J.D., Newlands S.D., Papaxanthis C., Angelaki D.E.
Multiple studies have demonstrated the brain’s ability to build internal representations of
environmental and musculoskeletal dynamics, allowing efficient motor planning. We have recently reported that both humans and monkeys optimally utilize the gravitational force when reaching in the vertical plane (Gaveau et al. 2013, 2016). Furthermore, vestibular signals are thought to allow the macaque brain to compute an internal model of gravity (Angelaki et al. 1999, 2004). The present study aimed at probing the potential role of vestibular signals in planning arm movements. Using a virtual reality system, three macaques were trained to perform single degree of freedom reaching movements between sets of two targets. The task consisted of shoulder flex/extension or shoulder ab/adduction. Kinematic and electromyographic (fine wire intra-muscular electrodes) signals were recorded from the right arm. After extensive training, two monkeys underwent a bilateral labyrinthectomy (ablation of the vestibular organs) and daily recordings were performed starting 24h post-surgery. Before surgery, we observed directional asymmetries on the kinematics of arm movements performed in the vertical plane but not in the horizontal plane (as previously reported). Precisely, the time to peak acceleration was shorter and the acceleration peak was larger for upward than for downward movements. These asymmetries result from specific patterns of muscle activations that (along with theoretical simulations) demonstrate the optimal integration of the gravitational force into the planning processes of reaching movements. After surgery, we observed specific modifications of movement kinematics in the vertical plane but not in the horizontal plane. First, spatial errors that differed between upward (undershoot) and downward (overshoot) movements were observed early after surgery (first 3 sessions). Second, the above-mentioned directional asymmetry disappeared or even slightly reversed; i.e. the time to peak acceleration being longer and the peak acceleration being smaller for upward than for downward movements. This effect lasted for about ten days and slowly vanished such that vertical movements progressively returned to normal (after 20 days). Overall, our results unveil the contribution of vestibular signals to optimizing the planning of reaching movements. Furthermore, these results suggest that remaining sensory cues (visual, somatosensory) allowed monkeys to progressively re-optimize the planning of vertical arm movements after labyrinthectomy.
Angelaki DE et al. (1999) Computation of inertial motion: neural strategies to resolve ambiguous otolith information. J Neurosci
Angelaki DE et al. (2004) Neurons compute internal models of the physical laws of motion. Nature
Gaveau J et al. (2013) Motor planning in the gravitational field: how do monkeys reach? SFN Annual meeting. 2013
Gaveau J et al. (2016) Direction-dependent arm kinematics reveal optimal integration of gravity cues. Elife
Vestibular contributions to hippocampal and striatal function
Paul F. Smith Dept. Pharmacology and Toxicology, School of Biomedical Sciences, the Brain
Health Research Centre, and the Brain Research New Zealand Research Centre, University of Otago, Dunedin, New Zealand.
Many studies have now demonstrated that lesions to, or stimulation of, the vestibular system, can alter neuronal activity in the hippocampus and striatum. Vestibular modulation of these areas of the brain is known to affect the development of both spatial memory and motor plans for action. Nonetheless, we still have a limited understanding of how vestibular input modulates hippocampal and striatal activity, and through what routes of synaptic transmission. This presentation will describe new studies in which we have investigated the effects of selective electrical stimulation of different parts of the rat vestibular labyrinth on electrophysiological activity in the hippocampus, using microelectrode arrays. We find that electrophysiological activity can be evoked by stimulation of all semi-circular canals as well as the utricle and saccule; however, the patterns of activation vary depending upon the structure stimulated, with greater responses evoked from the otoliths. The responses were bilateral and always greater than 20 ms in latency. In other related studies we investigated the pattern of c-Fos activation in the hippocampus resulting from selective vestibular stimulation and demonstrated that most of the neurons affected labelled for NeuN and were therefore were likely to be mature neurons. In further studies we have explored the effects of electrical stimulation of the rat vestibular labyrinth on single neuron activity, c-Fos expression and neurotransmitter release in the striatum. We found that a small, circumscribed number of striatal neurons responded with increases in firing; however, c-Fos expression decreased in a current-dependent manner. Using in vivo microdialysis, we have found that vestibular stimulation decreases the release of serine, threonine and taurine; dopamine was not significantly affected, however dopamine metabolism was decreased. We hope that these studies will contribute to a better understanding of how vestibular information is used by the hippocampus and striatum, both separately and together.
Cognitive repercussions of bilateral vestibular loss in humans.
B. Dobbels, MD 1,2, J. Moyaert, MSc 1, Prof. G. Mertens, MSc, PhD 1,2, Prof. P. Van de Heyning, MD,
PhD 1,2, Prof. V. Van Rompaey, MD, PhD 1,2
Presenting author: Prof. G. Mertens, MSc, PhD
1 Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital, Belgium. 2 Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.
PURPOSE. Hearing loss have recently been recognized as an independent risk factor of dementia.
Likewise, growing evidence suggest a link between the vestibular system and cognition. Our aim is to
evaluate spatial cognitive performance of 60 BVP patients with and without hearing loss.
METHODS. 60 patients (58.8 ± 14 YR) with an established diagnosis of bilateral vestibulopathy (BVP)
according to the Barany criteria were included. 49 healthy, normal hearing, controls (50y ± 17) were
selected. They had no vestibular complaints and presented a zero score on the Dizziness Handicap
Inventory. All subjects underwent audiometric evaluation. Spatial cognition was assessed by means of
the virtual Morris Water Maze test.
RESULTS. Overall patients with BVP took longer paths and time to reach a hidden platform in the
virtual Morris Water Maze test. Interesting, in a first statistical analysis were we did not correct for
hearing loss, the difference between the path lengths (trial 13-20) of the BVP group and healthy
controls was statistically significant. However, after correction for hearing loss, there were no
statistically significant main effects of BVP group anymore. Moreover, hearing loss seem to have a
statistically significant main effect.
CONCLUSION. Our results confirm the previous findings of impaired spatial cognition in BVP patients,
although in our study this effect seems to be attributed to the associated hearing loss in BVP patients,
rather than their vestibular loss.
Social modulation of vestibular information processing
Estelle Nakul*, Diane Deroualle, and Christophe Lopez
Aix Marseille University, CNRS, LNSC, FR3C, Marseille, France *Corresponding author: [email protected]
There is growing evidence that vestibular information contributes to cognition, affective
control and self-consciousness [1]. However, only few studies measured the reverse influence, that is, how cognition influences vestibular information processing. To date, no neurophysiological study has linked vestibular information processing and social cognition. This is surprising as humans are often surrounded by other individuals in motion, and as vestibular-defective patients frequently report imbalance when surrounded by other individuals in motion [2]. Here we studied how observing passive motion of human bodies influences vestibular information processing, measured by vestibulo-spinal excitability.
Twenty-five healthy volunteers wore a head-mounted display in which they observed 6-second videos depicting passive rotations around the vertical axis of their own body seated on a motorized chair (‘self’ videos), someone else’s body (‘other’ video) or an object (‘object’
video). While observing the videos participants received repeated galvanic vestibular stimulation with short pulses (2 ms, 8 Hz, 4 mA) through a cathode and an anode placed on the opposite mastoid processes. Galvanic stimulation stimulates vestibular nerve afferents and evokes short latency vestibulo-spinal reflexes, known as vestibular-evoked myogenic potentials (VEMPs) [3], which were recorded over the sternocleidomastoid and trapezius muscles.
For ‘self” compared to “object” videos, the amplitude of the VEMPs was significantly reduced at the p13 and the n23 on both the SCM and the TRP and around 60 ms on the TRP. For “other” compared to “object” videos, VEMPs were reduced at later components after 40 ms on both muscles. VEMPs were even smaller for ‘self’ than ‘other’ videos, revealing a social modulation of vestibular information processing, at the p13 and n23 on both the SCM and the TRP muscles and around 60 ms on the TRP.
Observing bodies in motion reduced vestibulo-spinal excitability, especially when observing oneself compared to others. This shows that processes linked to social cognition, such as the difference between the self and others, can modulate our sense of balance.
References [1] Lopez, C. 2016. The vestibular system: balancing more than just the body. Curr Opin
Neurol. Feb;29(1):74-83. [2] Lopez, C., Falconer, C.J., Deroualle, D., Mast, F.W. 2015. In the presence of others:
Self-location, balance control and vestibular processing. Neurophysiol Clin Nov;45(4-5):241-54.
[3] Welgampola, M.S. and Colebatch, J.G. 2005. Characteristics and clinical applications of vestibular-evoked myogenic potentials. Neurology May 24;64(10):1682-8.
Beaming into a robot: How visuo-vestibular synchrony influences body-self and social cognition
Ventre-Dominey J1,2 *, Gibert G1,2, Bosse-Platiere M1,2, Farnè A2,3,4,5, Dominey P1,2 † and Pavani F3,5,6 †.
1. Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France. 2. Univ Lyon, Université Claude Bernard Lyon 1, Lyon, France 3. Integrative Multisensory Perception Action & Cognition Team (ImpAct), INSERM
U1028, CNRS UMR5292, Lyon Neuroscience Research Center (CRNL), 69000 Lyon, France
4. Hospices Civils de Lyon, Neuro-Immersion, 69000 Lyon, France 5. Center for Mind/Brain Sciences (CIMeC), University of Trento, Italy 6. Department of Cognitive Sciences and Education, University of Trento, Italy
*Corresponding author
† Co-last authors
Recent studies have shown how embodiment (ownership or enfacement) induced by
multisensory bodily interactions between individuals can positively change self representation
and social attitudes (closeness, empathy, racial biases) (see Maister et al, 2015). Here by
using a simple neuroscience-inspired procedure, we show how head movements can lead to
beaming a human subject into a robot. Participants wore a Head Mounted Display (HMD)
tracking their head movements and displaying the 3D visual scene taken from the eyes of
either the iCub or Reeti robot, which were positioned in front of a mirror. As a result,
participants saw themselves as robots. Critically, when we made participants’ and robots’
head movements synchronous, participants judged the robot they beamed into as significantly
more likeable and socially closer. Control conditions whereby participants’ head movements
did not induce any movement in the robot’s head (static), or produced unmatched movements
(uncorrelated), produced instead a reduction of the robots’ social attraction. Remarkably, we
further found that the beaming experience with synchronous head movements and
corresponding sensation of embodiment and social proximity, was independent of robots’
human appearance, which was fulfilled by the iCub, but violated by Reeti. In some
participants, the beaming experience was strong enough to produce a likeability score
reversal, with respect to their initial preference. These findings not only reveal the plasticity
of self representation via synchronized visual-vestibulomotor interactions but also the ease of
body-swapping into robots even those with no clear human resemblance.
How vestibular disorders distort own-body perception and the sense of self Christophe Lopez1 et Maya Elzière2 1 Laboratoire de Neurosciences Sensorielles et Cognitives, CNRS and Aix Marseille Université, Marseille, France 2 Centre des Vertiges, Hôpital Européen, Marseille, France
How vestibular disorders affect own-body and self representations has been
overlooked, despite descriptions of depersonalisation-derealisation and cases of out-of-body experiences (OBE, the feeling that the self is located outside of the body) in patients with dizziness. This was explored in a large-scale observational, prospective study.
We measured the occurrence and severity of distorted own-body representations and OBE in the largest sample of patients with dizziness to date (n=350) compared to a group of age- and gender-matched healthy controls (n=350), using otoneurological examination, the Cambridge Depersonalization Scale, Hospital Anxiety and Depression Scale and the Palmer’s questionnaire for OBE.
Distorted own-body and self representations were more frequent and severe in patients with dizziness: 12% of the patients experienced their limbs have temporarily become larger or smaller, 37% reported abnormal sense of agency, 35% reported disownership for the body. We show a significantly higher occurrence of full-blown OBE in patients (14%) than controls (5%). Most of the patients experienced OBE only after they started having dizziness, and OBE was mainly related to peripheral vestibular disorders, never to bilateral vestibular failure. We identify depersonalization-derealization, depression and anxiety as the main predictors of OBE in patients, as well as a contribution of migraine.
We propose that OBE may arise from a combination of perceptual incoherence evoked by the vestibular dysfunction, with psychological factors (depersonalization-derealization, depression and anxiety) and neurological factors (migraine). This study should help understand the complex symptomatology of patients with dizziness, who present with alterations of the most fundamental aspects of their self.
Posters
1. Can Vestibular Signals Influence the Temporal Orienting of Attention? Saghi Arabi, Kent U.K. 2. Changes in body spatial representation after unilateral vestibular loss are modulated by the side of the
lesion and the post-lesion delay. Liliane Borel , Marseille, France 3. Neuro-behavioural Impairment in Military Veterans with Mild Traumatic Brain Injury and Vestibular
Disorder. Emma Denby , Kent, U.K. 4. Videonystagmography evaluation of dynamic asymmetry of vestibulo-ocular reflex (VOR) responses,
after unilateral peripheral loss. Comparison of passive rotational testing versus active head movements testing. Olivier Dumas, Lyon, France
5. Sharp foot pressure enables cortical sensory facilitation during natural standing: Combined behavioral, EEG and microneurographic approaches. Marie Fabre, Marseille, France
6. Getting ready for Mars: how the brain perceives new gravitational environments. Maria Gallagher, London U.K. 7. Vestibular Facilitation During a Virtual Morris Water Maze Task. Annita Gkioka, Kent, U.K. 8. Vestibulospinal control of axial and limb muscles : static, dynamic, and microgravity conditions. Etienne
Guillaud, Bordeaux, France 9. Changes in Functional brain activation with aging during hand movement perception. Caroline Landelle,
Marseille, France 10.How gravity influences vection induced by galvanic vestibular stimulation. Alexandra Séverac Cauquil,
Toulouse, France 11.Vestibular contributions to short-term memory. Laura Smith, Kent, U.K.
Can Vestibular Signals Influence the Temporal Orienting of Attention?
Saghi Arabi, Anka Davila, David Wilkinson.
School of Psychology, University of Kent, UK
There is wide agreement that the vestibular system influences spatial attention but it remains
unclear if this influence extends to temporal attention. To this end, we utilised the dynamic
attending paradigm which has shown that visual discrimination can be enhanced when the
appearance of visual stimuli coincide with a rhythmic auditory beat. This demonstration is
believed to reflect the capacity of auditory structure to entrain visual attention and to
facilitate future visual events that occur at the time of anticipated auditory beats. In the
present study, we tested whether rhythmic vestibular signals can likewise entrain visual
attentional responses. In Experiment 1, participants received rhythmic, sub-sensory, box-car,
bipolar, binaural (anode left, cathode right) GVS pulses discharged at a temporal frequency
of 2Hz and duration of 500ms. Throughout the stimulation period, participants completed a
delayed match to sample task in which they had to decide if Gabor patches, presented
singularly and several seconds apart, were the same or different. Critically, the onset of to-
be-matched stimuli always coincided with a GVS pulse, while the sample stimuli either
coincided with a GVS pulse or appeared before or after. We reasoned that if rhythmic
vestibular signals can summon visual attention to future moments in time then visual
judgements would be better when the visual stimuli coincided with the GVS pulse. Contrary
to expectation, increased response accuracy was observed at all visual onsets relative to
sham. This enhancement was replicated in another set of participants when the visual stimuli
were replaced with auditory stimuli (i.e. pairs of beeps that differed in pitch). In a second
experiment, we re-administered the visual and auditory tasks having first replaced the GVS
box-car pulse with a sinusoidal waveform that by virtue of alternating between positive and
negative amplitudes (all other stimulation parameters remained unchanged), successively
excited left and right vestibular nerves. This change in waveform eliminated the
enhancement, providing further evidence against vestibular-visual attentional entrainment,
and also giving reason to believe that the enhancement observed during anode left/cathode
right stimulation may reflect preferential up-regulation of right hemisphere. Together these
data fail to show that vestibular signals exert temporally-defined effects on attention, but do
uncover a new paradigm in which GVS can improve attentional discrimination.
Changes in body spatial representation after unilateral vestibular loss are modulated by the side of the lesion and the post-lesion delay
Bachelard-Serra M1, Bernard-Demanze L1, Honoré J2, Saj A3, Lavieille JP1, Borel L4
1 Service ORL et Chirurgie Cervico-faciale, Hôpital de la Conception, AP-HM, Marseille 2 Laboratoire Sciences Cognitives et Affectives (SCALab), UMR 9193, Université de Lille, Lille 3 Neurology Department, Geneva University Hospitals, Geneva, 4 Laboratoire de Neurosciences Intégratives et Adaptatives, UMR 7260, Aix-Marseille Université/CNRS, Site Saint Charles, Marseille
Key words: Subjective visual straight ahead; Spatial orientation; Vestibular lesion; Recovery course; Vestibular asymmetry ABSTRACT
Introduction: The unilateral vestibular syndrome results in postural, oculomotor, perceptive
and cognitive symptoms. The present study was designed to investigate the role of vestibular signals in body orientation representation, which remains poorly considered in vestibular patients. Methods: The subjective straight ahead (SSA) was investigated using a method disentangling lateral shift and tilt components of error. In the horizontal plane, subjects were required to align a rod with their body midline. In the frontal plane, they were asked to align the rod with the midline of head or trunk. Patients with right (RVN; n =14) or left vestibular neurotomy or vestibular schwanoma resection (LVN; n=8) were compared with 14 healthy controls. Patients were tested the day before surgery and during the recovery period, 7 days and 2 months after the surgery. Results: In the early stage after surgery, all the patients showed an ipsilesional deviation in translation and in rotation. Before the operation and during the compensation stage, the patients with LVN showed a controlesional translation of their SSA, whereas those with RVN had an ipsilesional deviation which did not differ from that of the controls. Discussion-Conclusion: This work constitutes the first description of the immediate consequences and of the recovery time-course of body orientation representation after unilateral vestibular loss. Interestingly, deviated body representations were mainly observed when the neurotomy was performed on the left side. These data support the hypothesis of an asymmetric vestibular function in healthy subjects.
Neuro-behavioural Impairment in Military Veterans with Mild Traumatic Brain Injury
and Vestibular Disorder
Emma Denby1, Dominic Murphy2,3, Walter Busuttil2, Mohamed Sakel4 & David Wilkinson1
1School of Psychology, University of Kent, Canterbury, UK. 2Combat Stress, Tyrwhitt House, Leatherhead, UK.
3King’s Centre for Military Health Research, King’s College, London, UK. 4East Kent Neuro-Rehabilitation Service, East Kent Hospitals University
NHS Foundation Trust, Canterbury, UK.
Chronic dizziness and imbalance of vestibular origin are commonly reported in military
veterans with mild traumatic brain injury (mTBI), but beyond these symptoms the long-term
impact of vestibular disorder on cognitive and affective function is uncertain. To address these
questions, 162 UK military veterans with a lifetime history of mTBI and in receipt of
psychological support completed the Neurobehavioral Symptom Inventory, Headache Impact
Test, Epworth Sleepiness Scale, Memory Complaints Inventory, PTSD checklist for DSM-5,
and the Kessler Psychological Distress Scale. Vestibular function was assessed using the
Vertigo Symptom Scale, and general functional disability was measured using the WHO
Disability Assessment Scale 2.0. 72% of the sample reported one or more mTBI over their
lifetime. Chi-square analyses indicated that vestibular dysfunction, which affected 69% of
participants, was equally prevalent following blunt (59%) or blast (47%) injury and most
prevalent following blunt and blast combined (83%). Over three-quarters of the sample
reported cognitive (i.e. perceptual, executive, motor coordination) and affective (i.e.
depression, anxiety, PTSD) symptoms. Mediation analysis indicated that when the known
predictors of PTSD, depression and anxiety were taken into account, vestibular dysfunction
was directly and independently associated with increased cognitive impairment and functional
disability. We conclude that vestibular dysfunction is especially common after combined blunt
and blast mTBI and predictive of poor long-term mental health. From a treatment perspective,
we propose that vestibular rehabilitation, although uncommonly prescribed, may provide relief
from post-concussive symptoms other than dizziness and imbalance.
Videonystagmography evaluation of dynamic asymmetry of vestibulo-ocular reflex (VOR) responses, after
unilateral peripheral loss. Comparison of passive rotational testing versus active head movements testing
Dumas O.(1), PT, Miséré T.(1), PT, Ortega Solis J.(1,2), PT, Bécaud C.(1,2), PT, Chabbert C.(3), PhD, Lopez C.(3), PhD, Hitier
M.(3), PH, MD, PhD, Tilikete C.(4), MD, PhD
(1) Société Française de Kinésithérapie Vestibulaire (SFKV)
(2) Audiology Service HFME, HCL, Lyon, France
(3) Aix Marseille University, CNRS, Laboratory of Sensory and Cognitive Neurosciences UMR7260, Marseille, France
(4) INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, IMPACT Team; Lyon I University, Lyon, F-
69373, France; Neuro-ophthalmology Unit, Hôpital Neurologique et Neurochirurgical P. Wertheimer, Lyon, France
Background and Purpose
Rotational Chair Testing (RCT) is commonly used to evaluate VOR gain and symmetry (VORS). Based on our
experience, recovery of VORS, in patients after acute unilateral loss, measured by RCT is not always
correlated with quality of live improvement measured by DHI scale. However, when VORS is evaluated with
active head movements testing (AHMT) it seems that there is a better correlation between symmetry
recovery and DHI improvement. The goal of this study is verifying this hypothesis.
Methods
This is a retrospective longitudinal study, 51 patients 28 to 68 years of age, 27 males and 24 females were
recruited in 2 PT private practice, the control group were 30 healthy subjects. Inclusion/exclusion criteria
were: acute unilateral loss diagnosis (vestibular neuritis) lateral canal paresis showed by caloric and vHIT
evaluation, DHI score > 50, persistence of spontaneous nystagmus beating toward the unaffected ear and
VOR directional preponderance > 6°/s. Patients received VR treatment for one month twice a week in a PT
practice as well as home exercises program. At the beginning of each VR session patients completed DHI
followed by evaluation of VORS, RCT and AHMT, that was done in randomized order. RCT evaluation
was sinusoidal test, 0,25 Hz, 60° range, duration 32 seconds. For AHMT subjects were asked to do the same
movements as sinusoidal test, an audio-cue system was used to guide head movements frequency, VOR and
head speed values were corrected by an algorithm.
Results
The main parameters studied for each paradigm, active head movements testing (AHMT) and Rotational
Chair Testing (RCT), were: horizontal VOR directional preponderance (degrees/second), calculated as
cumulative slow-phase eye position at the end of acquisition (degrees) divided by duration of test acquisition
(seconds), and his correlation with DHI results.
We noticed that, from the second treatment session: VOR directional preponderance diminution with AHMT
paradigm was statistically significant greater than VOR directional preponderance diminution with RCT
paradigm, p<0,05 (Student’s t-test).
Correlation between VOR directional preponderance diminution with AHMT paradigm and DHI results
diminution (r=0,9) was statistically significant greater (p<0,05) than correlation between VOR directional
preponderance diminution with RCT paradigm and DHI results diminution (r=0,6).
Discussion and conclusion
According to this study VOR symmetry evaluation with active head movements testing paradigm (AHMT)
shows a stronger correlation with changes of the quality of life of the patient measured by DHI scale,
compared with Rotational Chair Testing paradigm (RCT). Thus AHMT paradigm seems more relevant for
vestibular rehabilitation assessment of patients with vestibular neuritis as well as probably for other patients
with acute vestibular unilateral hypofunction evaluation.
Sharp foot pressure enables cortical sensory facilitation during natural standing:
Combined behavioral, EEG and microneurographic approaches
Marie Fabre1, Marine Antoine2,3, Mathieu Germain Robitaille2, Edith Ribault4, Rochelle Ackerley4, Jean-Marc Aimonetti4, Pascale Chavet5 , Jean Blouin1, Martin SimoneauCA,2,3,
Laurence MouchninoCA,1
CA Co-last authorship: Martin Simoneau and Laurence Mouchnino contributed equally to the direction of this work
1 Aix-Marseille Université, CNRS, Laboratoire de Neurosciences Cognitives, FR 3C, Marseille, France 2 Faculté de médecine, Département de kinésiologie, Université Laval, Québec, QC, Canada 3 Centre interdisciplinaire de recherche en réadaptation et intégration sociale (CIRRIS), Québec, QC, Canada 4 Aix-Marseille Université, CNRS, Laboratoire de Neurosciences Sensorielles et Cognitives, Marseille, France 5 Aix-Marseille Université, CNRS, ISM, Marseille, France
Natural standing is a dynamic phenomenon and relies on body representation in space and on sensory signals primarily coming from the feet. Different hypothesis has been proposed to explain how it is controlled. But none of them totally explained fluctuations between large and small body sways characterized by center of pressure – center of mass (CP-CM) distance. We hypothesized that during natural standing, small body sways (i.e. staying in the narrow support area) may be unable to generate full somatosensory transmission to the cortical level due to skin compression (i.e. depressed transmission). In such circumstance, predictive mechanisms would trigger a large body sway to gather plantar tactile information. To this aim, The P50N90 somatosensory evoked potential (SEP) and brain cortical activities were compared in 17 young adults between Large sway and Small sway condition. Our results showed an increased P50N90 SEP amplitude during large sway as compared to small sway. In addition when using a microneurography technique we reported a suppression of tactile fibers discharge following a continuous pressure applied to the mechanoreceptors. Both the cortical SEP and fibers. Overall these results suggest that large sway constitutes a relevant strategy for releasing skin compression and facilitates tactile afferents transmission in order to update body position in space. The predictive control of Large sway to release skin compression is strengthened by the fact that cortical areas (SPL, SMA, dl PFC) known to be engaged in motor planning are activated before Large sway onset. The observed ankle muscle activation prior to large sway confirmed the presence of a central command aiming to prevent tactile afferent inflow to dry up during natural quiet standing.
Getting ready for Mars: how the brain perceives new gravitational environments
Maria Gallagher1*, Agoston Torok2*, Camille Lasbareilles1, and Elisa Raffaella Ferrè1
1Royal Holloway, University of London
2Hungarian Academy of Sciences
*Joint first authors
On Earth, we are continually exposed to the force of gravity. Gravity is detected by online
sensory signals which are integrated to form an internal model of gravity. Understanding
whether this model can adapt to new gravitational environments is vital as humans push the
boundaries of space exploration. Here we explored whether the internal model of gravity
could be applied to new gravitational environments. On Earth, observers are more accurate
at judging the speed of falling versus rising objects, as they comply with gravitational laws.
We investigated whether participants showed the same “gravitational advantage” when they
observed objects moving under a visually-simulated Mars gravity environment. Participants
were shown a scene where a ball moved upwards or downwards under Earth (9.81 m/s2) or
Mars (3.71 m/s2) gravity. Participants memorised the speed of the ball moving at a constant
speed, then judged whether variable-speed trials were faster or slower than the memorised
speed. Participants showed the same advantage for falling stimuli under both Earth and
Mars gravity: downwards movement was more accurately detected than upwards
movement. Although the internal model of gravity has been built up under Earth gravity, our
results suggest that it can quickly adapt to a new gravitational environment.
Vestibular Facilitation During a Virtual Morris Water Maze Task
Annita Gkioka, Laura Smith, David Wilkinson
School of Psychology, University of Kent, UK
Clinical, animal and human behavioural data suggest that the influence of the vestibular system
extends beyond that of balance and autonomic control to various cognitive functions, most
notably visuo-spatial memory. However, the psychological processes that underlie this
interaction remain unclear. To investigate this issue, we previously employed a visual search
task to show that participants are significantly quicker at finding a pre-determined target when
it appears in a spatial location previously associated with a unique vestibular signal as provided
by a brief, sub-sensory pulse of galvanic vestibular stimulation (GVS). This advantage is
evident even when the search array is inverted by 90 degrees, indicating that it is spatially
relative rather than absolute. The current poster expands on this work by presenting preliminary
results from data collected using a 2D version of the Morris Water task which aims to more
specifically test if the GVS advantage is spatial- as opposed to object-based. An important
benefit of using such a task is that its simplicity makes it well–suited for individuals with
amnesia. Preliminary data show a trend for targets to be more easily found when located at a
position that has been primed with a sub-sensory GVS pulse. Theoretical implication aside,
this finding gives reason to now administer the task to individuals with spatial memory
impairment (e.g. Alzheimer’s patients) to help assess the rehabilitative relevance of GVS.
Keywords: Vision, Spatial memory, Sensory stimulation, galvanic stimulation,
Alzheimer’s disease
VESTIBULOSPINAL CONTROL OF AXIAL AND LIMB MUSCLES: STATIC, DYNAMIC AND MICROGRAVITY CONDITIONS
Etienne Guillaud1, Céline Faure1,2, Emilie Doat1, Dominique Guehl3, Jean-René Cazalets1
(1)INCIA, CNRS & Université de Bordeaux, Bordeaux, France (2)CIRRIS, Université Laval, Québec, Canada (3)CHU Pellegrin, EFSN, Bordeaux, France
Corresponding author: [email protected] Preferred format: POSTER
During evolution, locomotion has evolved, switching from a propulsion by undulation to quadrupedal and finally bipedal propulsion, strengthening the difficulty to maintain balance. The ability to adjust body orientation highly relies on the vestibular system, which provides adequate informations related to head movement and orientation. Some vestibulo-motor responses, like vestibulo-ocular or vestibulo-colic reflexes, are strongly automatic and occur with very short latencies. At a lower level of automaticity, vestibulo-motor responses in lower limbs directly depend on limb engagement in the current task, and require longer delays to occur. Most studies that have addressed the control of balance of upright subject, have mainly investigated the role of lower limbs, while little attention has been paid to the vestibulospinal reflexes that take place in the back muscles. This is surprising since the trunk, that represents more than 60% of the total body mass, is located above the center of gravity, is highly articulated and actuated by many muscles. An active control of the paraspinal muscles should be of importance in all situations of the life to maintain balance as well as body orientation.
Our objective in the set of experiments presented here, was to challenge the persistence of vestibular evoked responses in back muscles in situations where leg muscle responses were modulated by the task and/or the context. Nineteen subjects were submitted to binaural bipolar galvanic vestibular stimulations (GVS) to generate a vestibular signal of imbalance, and trigger postural adjustments. Vestibular evoked myogenic potentials (VEMPs) were recorded in paraspinal and limb muscles, in addition to the body sway (kinematic and ground reaction forces). In laboratory, subjects were tested in upright standing, head turned and eyes closed. Postural sways occurred in directions that depended on the anode position (front or back), and VEMPs were recorded in Gastrocnemius Medialis and Paraspinal muscles (L4 level). If a slight head contact was provided to the subject, VEMPs remained uniquely present in the paraspinal muscles, and disappeared from the lower limbs. The same phenomenon was observed when the subjects were sustained upright in a hip harness. In a second series of experiments, subjects were submitted to GVS during walking on a treadmill. In the lower limbs, the occurrences of VEMPs was dependent on the phase of the gait cycle (stance or swing phase), whereas VEMPs in paraspinal muscles remained constant over the phases. Lastly, in our most challenging condition, we tested the persistence of vestibulospinal reflexes on free floating subjects in the “absence” of gravity during parabolic flight. In this condition, we hypothesized that VEMPs would disappear as no constraint of gravity neither on posture nor on balance was present. Surprisingly, we observed a persistent postural response at the paraspinal level, while it was suppressed in the limb muscles. When the experiment was performed while the subjects were held by foot-straps, providing them proprioceptive feed-back at foot and ankle level, and allowing them to counteract the detected imbalance, VEMPs were still suppressed in lower limb muscles while persisting in axial muscles.
Altogether, our results suggest that there exists a differentiated control mechanism of axial and appendicular muscles when a body rotation is detected by vestibular inputs. The persistent feature of myogenic adjustments suggests an irremovable reflex functionally efficient to maintain the posture. In contrast, the response to vestibular perceived unbalance takes place at the ankle only with congruent sensorial feed-back, challenging balance task and gravity. Postural responses following GVS in microgravity have never been documented, and this appeared to be an exciting approach to unravel some aspects of vestibular control in a totally unconstrained system.
C Landelle, JL Anton, J Sein, B Nazarian, O Félician, A Kavounoudias
Functional brain activation associated with impairment of hand movement
perception based on muscle proprioception and touch in older adults
How gravity influences vection induced by galvanic vestibular stimulation. Alexandra Séverac Cauquil, Philippine Picher, Caroline Vilarem, Maxime Rosito
CerCo UMR 5549 CNRS Université Toulouse 3 Galvanic stimulation of the vestibular apparatus (GVS) has been widely used in posture investigations. The oculomotor and postural responses to GVS suggest that it mimics an anteroposterior or lateral tilt, according to the electrodes position and polarity. It has been reported that GVS could induce vection, or self-motion illusion, but this was not extensively studied. Here we measured the rate of GVS-induced vection in standing and lying-down subjects, in order to assess the influence of gravity. To prevent our subjects from any motion induced by GVS and therefore enable the vection occurrence, they were maintained firmly strapped to the reclining chair for lying down and a vertical frame for standing conditions. In a forced-choice task, subjects were instructed to indicate whether they felt a tilting towards the left, right, back or forth. We expected GVS-induced to be more accurate while standing than lying down. Twenty subjects were included in the study, to whom we applied 0.5 to 1.5 mA stimuli during 2 to 4 s through 4 electrodes stuck on the forehead and the mastoid processes. We found that the precision was higher in the anteroposterior than the lateral plane and for longer duration stimuli. The position with respect to the gravity did not change vection accuracy. This is essential since GVS can be used as a vestibular stimulation tool in fMRI setup, where the subjects is in supine position.
Vestibular Contributions to Short-Term Memory
Laura Smith*, Annita Gkioka, David Wilkinson The University of Kent
The diverse anatomical projections of the vestibular system offer a neural substrate through which vestibular inputs could influence memory. However, few studies have tried to characterise this association at the psychological level. To this end, I will present three interlinked projects which offer new insights into the range and manner in which vestibular signals interact with memory processing: 1) Cross-sectional data from neuro-otological patients (N= 101) and older adults (N= 80) reveal that vestibular function can exert a direct effect on visuospatial memory processes, independently of comorbid psychiatric and fatigue symptoms; 2) traumatic brain injury patients (N= 8) treated with caloric vestibular stimulation show isolated improvements in attention and memory but not comorbid psychiatric and fatigue symptoms; 3) the application of galvanic vestibular stimulation can help normative samples to individuate one spatial location from another. Results will be discussed in relation to mechanistic accounts of vestibular contributions to memory and allied cognitive processes. Implications for the diagnosis and management of vestibular, neuropsychiatric and amnesic conditions will also be considered.